The government and Royal Mail management argue that the organisation needs access to private capital in order to grow and compete with its rivals – such as UK Mail and TNT, who have capitalised on the rise in online shopping – despite its profits more than doubling in the last financial year. Business secretary Vince Cable argues that the decision is designed to make Royal Mail a sustainable business, and says privatised postal services already work successfully in Austria, Germany and Belgium.

However, others are concerned that services will suffer after the sell-off, which is set to happen before spring 2014. Save our Royal Mail, with which the Guardian is running fringe events at the upcoming party conferences, has gathered a petition with more than 125,000 supporters. The group says the decision has not been sufficiently debated in parliament – the first Commons debate took place only at the beginning of this month – and that the public, as well as businesses, will inevitably lose out if postal costs go up and services suffer. The privatisation plans are also under threat from potential strikes by postal workers, who are being balloted in the coming weeks over pay, jobs, pensions and the impact of the sell-off.

Backed by the Communication Workers Union, National Pensioners' Convention and Manchester city council, the group has put pressure on politicians to state publicly that when the sale happens some of the unique aspects of Royal Mail's services will be safeguarded. A key part of the debate is the Universal Service Agreement, which requires Royal Mail to deliver to all homes in the UK six days a week. Because this is not cost-effective in sparsely populated areas, opponents believe the level of service will eventually be reduced by Royal Mail's new owner, affecting those in rural communities as well as elderly people.

Our livechat and fringe events will ask whether modernisation must inevitably result in Royal Mail being privatised or whether it could still thrive in the public sector.